Manufacture of string or the like



AM 22 1941. 4. H. WATSON Em 2,4 9 3 8 I MANUFACTURE OF STRING OR THELIKE Filed NOV. 13, 1944 Patented Apr. 22, 1947 MANUFACTURE OF STRING ORTHE LIKE John Hill Watson and Hugh Edward Anderson,

Linwood, Scotland, and

Beaconsfield, England Application November 13, 1944, Serial No. 563,314In Great Britain August 10, 1943 1 Claim. 1

This invention relates to the manufacture of string and binder twineproduced from paper yarn, more especially yarn formed from paper inwhich the paper web is treated, before drying, with the constituents ofa polymerisable or condensible synthetic resin and thereafter set byheating. I

According to the present invention, the paper string or twine'iormedfrom paper treated as described above is coated or impregnated with 2 to3% of its dry weight of partially condensed thermosetting artificialresin, e. g., urea-formaldehyde or phenol-formaldehyde resin, that isnot yet fully condensed or' polymerised, and then drawn through a heateddie to effect condensation and bonding, so that subsequent unravellingof the strands is prevented or made difiicult.

The coating or impregnation may be effected by causing the string ortwine to pass through a bath containing a solution of the uncondensedresin, then between rolls, and then through a heated die, the rate beingso adjusted that the temperature of the string or twine rises to theneighbourhood of 130 C.

The string or twine so treated may be subjected to subsequent heattreatment to effect complete condensation or polymerisation of theresin.

The quantity of resin used in coating or impregnating the string isabout 2 /g% to 3% reckoned on the weight of the dry string.

Important properties of string or twine manufactured ,as described area) strength, both when dry and wet, (b) yin-31 repellency, (c) insectand mildew proofn s, and (d) flexibility, as for handling in binders andtying machines.

In other words, bearing in mind that the paper string or tWine comprisesa multiple number of strands, there are realised maximum tensilestrength, optimum flexibility, water repellency, high wet rength, andresistance to attack by insects d mildew.

T invention will be further described in connection with the attacheddrawing which di- /agrammatically illustrates one form of apparatuswhich may be used in producing the impregnated cordage.

Referring to the drawing, the cordage I is formed from a plurality ofstrands of paper impregnated with the constituents of a thermosettingresin and passed over a guide rule 2 into a bath 3 of a partiallycondensed or partially Edward Reeve Angel,

polymerized thermosetting resin. The cordage is guided through the bath3 by a series of guide rules 4 beneath which the cordage passes. Onemerging from the bath, the cordage passes around a guide rule 5 andthen between rolls 6, after, which it is passed through a die 1 heatedin any appropriate manner, as by an electric coil'8. The die shapes thecordage to the desired final form and exerts suflicient pressure againstit to cause the several strands thereof to be bonded to one another. Thedie is heated to such temperature that the cordage in passingtherethrough is heated to a temperature in the neighborhoo'd of C. sothat further condensation of the resin will take place simultaneouslywith the formingof the cordage into its final form.

If desired, the cordage after leaving the die 1 may be subjected tofurther heat treatment in order to effect complete condensation orpolymerization of the resin.

We claim:

The method of producing impregnated cordage which comprises formingcordage from a plurality of strands of paper impregnated withconstituents of athermo-setting, synthetic resin, impregnating thecordage thus formed with a partially condensed thermo-setting,artificial resin, drawing the impregnated cordage through a die of suchsize and at such temperature that it is shaped to desired cordage formand the strands forming it are bonded to one another simultaneously withfurther condensation of the thermo-setting resin.

JOHN HILL WATSON. HUGH EDWARD ANDERSON. EDWARD REEVE ANGEL.

REFERENCES DITED The following references are of record in the

